"I never lost consciousness," said the retired colonel. "I lost track of who I was, and where I was, for a while as he kept picking me up and throwing me across the room."

Although it's been 30 years since Hubbard was a POW, he is 99 percent certain he knows the identity of Fidel.

Based on a picture that was taken in 1957, 10 years before his torture in Hanoi, Hubbard has fingered Fernando Vecino Alegret, who is now Cuba's Education Minister.

"It's more than just the appearance," said Hubbard. "It's the sneer on his face that is exactly what I saw every day as he was interrogating me."

At least one other former POW agreed the picture of young Alegret strongly resembles "Fidel".

The Cuban government has issued a denial.

"It is totally ridiculous and false. The minister himself has said that he has never even been in Vietnam," said Cuban Foreign Ministry spokesman Alejandro Gonzalez.

Hubbard has identified Alegret once before. He first picked him out in 1979 from photographs provided by the FBI. But Alegret was then older, heavier and balding -- so Hubbard wasn't as sure of the identification.

An aerial photo of 'The Zoo' prison camp in Hanoi, Vietnam

"I wouldn't want to stake my entire life's savings on it, but I would come awfully close to that," said Hubbard.

"I'm relatively confident -- not only because I saw two different pictures taken 20 years apart and picked the same guy out of the crowd both times," the former POW said.

Critics of the Castro regime are calling for the case to be reopened.

"Some people say, 'Hey, been there, done that -- Vietnam was an old chapter in our nation's history,' but I think it's important to look at history," said Rep. Ileana Ros-Lehtinen (R-Florida).